The Mexican Children of Immigrants Program project is composed of three interrelated research projects that assess how contexts affect health and health care access among Mexican children of immigrants. Together, the three projects will examine the effects of the multiple contexts within which children live: from the proximate context of the family to the intermediate contexts of schools and neighborhoods to the more distal contexts of the community, state, and nation. The project involves a mixed group of senior- and mid- level researchers from three departments at The Pennsylvania State University and a senior scholar from University of California at Irvine. It also includes a mentoring component that will involve two junior minority scholars who hold faculty appointments at The Pennsylvania State University and a dissemination component that is based on collaborative arrangements with the Migration Policy Institute in Washington, DC. The program project has four overarching objectives: (1) to build an interdependent team of researchers by fostering the exchange of ideas, methods, and data in order to make significant advances in the area of immigrant health;(2) to assess interethnic differences (Mexican-American children compared with non-Hispanic black and white children) and intra-ethnic differences (variations among Mexican- American children by parental nativity, level of assimilation and legal status) with respect to health-related outcomes, exposures to various contexts, and the association of contexts with health-related outcomes;(3) to develop and implement new methods for quantifying and adjusting for the effects of immigration and emigration selection bias to better interpret findings on the distinctiveness of Mexican children of immigrants and immigrant assimilation;and (4) to disseminate research findings as broadly as possible to the academic community and to nonacademic policymakers and other stakeholders. In addition to the three research projects, two service cores are proposed to facilitate these aims, the Administration and Dissemination Core and the Migration Methodology Core. PUBLIC HEALTH RELEVANCE: This project will examine the roles of family, school and neighborhood contexts in Mexican-origin children's health care and health. Scientific knowledge of the factors that place Mexican children at risk of physical, behavioral, and developmental disorders is limited. The proposed research will produce essential knowledge for the development of sound public policies and interventions to reduce health disparities.